It is conventional practice in installation of electrical and plumbing conduits to terminate the conduit pipe or tube in a fitting of a union or other coupling device. The fitting typically comprises a collar or sleeve brazed onto the tube end and having a periphery contoured to be sealingly captured between coupling members. It is critical in brazing the collar onto the tube end that they be heated in a controlled and uniform manner so as to obtain proper flow, distribution and metalurgy of the brazing alloy.
Conventionally, the tube end and sleeve are heated by manipulation of a specially-contoured brazing torch. The process is thus dependent upon training and dexterity of the technician, and results are not always satisfactory. Heat control and distribution remain a limiting factor in construction of satisfactory brazed tube/sleeve end fittings, particularly where brazed in the field under adverse working conditions.
It is therefore a general object of the present invention to provide apparatus for heating a tube/sleeve end fitting for brazing that obtains controlled and uniform heat distribution around the fitting components, requires minimum operator intervention and skill, is quick and easy to use, avoids the fire and, explosion hazards of an open flame, is economical to assemble and sufficiently portable as to be readily transportable to a job site, is constructed to accommodate a variety of tube and sleeve diameters, of economical manufacture and assembly and provides reliable service over an extended operating lifetime.